Every wine grape originates from the same species: Vitis vinifera. When we discuss a grape's "varietal," we're referring to a specific "cultivar" within that species—that is, a particular strain that has been cultivated into its current form.
Grapes grow all over the world, in vastly different regions, over different terrains and within different climates. Some have been selectively bred, shaping them into more than 1,300 varietals of grapes used to make wine today. Being comfortable talking about a wine requires understanding where it comes from—and learning how to pronounce the names of the grapes in it is a logical place to start.